Hans directed me to a hotel in central Jerez (about 20 mins drive ISTR) which was about £20 pn plus parking; I had a very cheap car (again Hans directed me to a company), about a tenner a day I think. The hotel was right in the centre, and too noisy for me, but otherwise was ok. Taxi might have been cheaper and easier.
Something I hadn't anticipated was the propensity for local restaurants to not open till very late (imho).
The Ryanair flight was absolute peanuts. (I took my own ha ha)
Andy